Decalcomania paper



Dec. 10, 1935. L, DAVIS 2,023, 03

DECALCOMANIA PAPER Filed May 51, 1934 //\/I/ENTOR.'

Patented Dec. 10, 1935' UNITED STATES PATENT -OFFICE Laurin-Jones 00.,Brookfield, Mass, a corporation of Massachusetts Application May 31,1934, Serial No. 728,234 9 Claims. (Cl. 41-33) This invention relates todecalcomanias and to the papers on which decalcomania designs areprinted.

In applying such designs to some articles of work, especially woodveneers, the use of the necessary quantity of water required to separatethe backing sheet from the decolcomania film is highly objectionablebecause it tends to warp the veneer and makes it difficult to properlyregister or abut the edges of adjoining sheets. If, in addition, theveneer is to be applied to a wood or other absorbent body or core, whichusually is the case, the application of water is still moreobjectionable. While this difficulty is not particularly serious whenthe decalcomania design is to cover only a small portion of the work, itis an important factor in applying such designs to the entire surface ofa veneer sheet or other absorbent body.

. The present invention deals with this problem and aims to devise athoroughly practical 561w tion for it.-

The nature of the invention will be readily understood from thefollowing description when 5 read in connection with the accompanyingdrawing, and the novel features will be particularly pointed out in theappended claims.

In the drawing, Figure 1 is a perspective view of a decalcomania 30paper embodying features of this invention; and Fig. 2 is a vertical,sectional view through the sheet shown in Fig. 1.

The product shown in the drawing comprises a backing sheet A of papercarrying on one face 35 thereof three superposed coats of waterresistant material, the respective coatings being designated at I, 2 and3. The first and third of these coats may conveniently be of essentiallythe same composition and both soluble in somenon-aqueous 40 liquid. Theintermediate coat 2, however, should be composed of some substance whichis highly resistant to the solvent for the other two coats. In otherwords, it is important that each of these coating materials be readilysoluble in a solvent 45 to which the other is highly resistant. From acost standpoint it is desirable also that the solvents which must beused in practice be relatively in expensive.

I have found that these requirements can be satisfactorily met by makingthe first and third coats of the synthetic resin known commercially ascumar, and the intermediate coat 2 of gum sandarac. Diluents may be usedwith either con- ,stituent. Cumar is known chemically as acoumaronedndene resin and may be defined as a mixture of para-coumarone,para-indene, and the polymers of other hydrocarbons found in coal tar.It is a neutral resin produced from coal tar distillates and is solublein a considerable 5 variety of common solvents such as gasolene andother petroleum distillates. ethyl and amyl acetates, carbontetra-chloride, and others. It is, however, insoluble in either alcoholor ether. Gum sandarac is substantially unaffected by the 10 solventsabove mentionedfor cumar, but is readily soluble in ethyl alcohol,methyl alcohol, amyl alcohol, and ether. Consequenty, these resinoussubstances satisfy the present requirements.

In-preparing the coating materials for application to the backing sheet,it should be borne in mind that the outer coating 3 must be very flat,smooth, and free from imperfections since the decalcomania design willbe printed on this surface. For this reason it is desirable to associatesuitable plasticizers with the cumar resin and the solvents for it inorder to produce a coating of the desired smoothness. Since the leastexpensive of the solvents for the cumar consists of gredients:

Grams Cumar- 814 Eethyl aceta 424 Butyl cellosolve s 12 r Dibutylphthalate 48.5 Troluoil 725 Of these constituents the chief solvent isthe troluoil which is a petroleum distillate having a boiling range offrom about 99 to 116 C. Other 40 petroleum fractions, however, can besubstituted for it. The ethyl acetate is a solvent aid. The dibutyl'phthalate is a plasticizer, and the butyl cellosolve (ethylene glycolmonobutyl ether) performs similar functions, acting as a leveling agent.

This composition produces a very smooth satisfactory coating suitable.for both the first and last coats l and 3. I

For the intermediate coat 2 a solution of gum sandarac alone indenatured alcohol can be used. However, it is preferable from a. coststandpoint to reduce the quantity of gum sandarac used by some suitablediluent such as rosin (c'olophony), shellac, orthe like. A compositionsuitable togo with that above described consists of the following:

Grams Gum sandarac 778 Rosin 1036 Denatured alcohol (Formula #5) 910 Inthe process of manufacture either a sized paper or an absorbent sheetsuch as that commonly used heretofore in the manufacture of decalcomaniapaper, may be used for the backing sheet A. The coat I of cumar preparedin the manner above described is applied to the surface of this backingsheet and, when this coating has dried suiiiciently, the second coat 2of rosin sandarac mixture is applied, the final coat of cumar beingsuperposed on the intermediate coat 2 after the latter has dried. Thepaper so prepared is shipped to the decalcomania manufacturer who printshis design on the surface of the outer coat 3. The decalcomania soproduced may be of the ordinary transfer variety or of the socalledslide off type. In either event it is freed from the backing sheet 2during the application of the design to the work by applying a solventsuch as ordinary gasolene, toluol, troluoil, or the like, to the backingsheet, thus softening the inner coat I of cumar, and permitting thebacking sheet to be pulled off. During this operation the intermediatecoat 2 of rosin sandarac mixture protects the outer coat and the designprinted on it from the action of the solvent.

In some cases the innermost coat I of cumar can be omitted, the coat ofrosin sandarac mixture being applied to the paper first and the cumarcoat on top of it. In such an event the backing sheet is removed byapplying alcohol or one of the other sandarac solvents to it. It is moresatisfactory, however, to use three coats since the coat 2 is somewhatspongy and porous in character and it may be penetrated by portions ofthe upper coat during the application of the latter and produce astaining of the backing sheet which would be objectionable from thestandpoint of saleability of the goods.

In making the cumar composition it is preferable to use the hardestgrade of this resin, especially for the outer coat, and to make asolution of a fairly high concentration, say at least Other gums, suchas ester gum, can be used instead of part or all of the cumar resin,although I have not found it as satisfactory as the latter. By ester gumI mean the compound which also goes under the names of rosin ester orglycerinated rosin. Araclor resin can also be used to supplant a part ofthe cumar. This resin consists of chlorinated diphenyl and otherchlorihated diaryls. While, as above stated, I prefer to use gumsandarac as the chief constituent of the intermediate coat, other gumssoluble in alcohol can be substituted for it, such for example, asdewaxed dammar gum. I have found nothing, however, as satisfactory forthis purpose as gum sandarac.

An important advantage of the product above described is that theoutermost cumar coat is not substantially affected by the more commonsolvents used in the inks with which the decalcomania designs areprinted on this surface. Also, it is a common practice to apply acoating of clear lacquer over the decalcomania design, and the cumarresin coat is highly resistant to the solvents commonly used in theselacquers. In some cases, however, an ink may be used which, from a.chemical point of view, is really a varnish or paint,

and includes a vegetable oil or some other constituent which does attackthe cumar coat. Inks of this type, however, are practically insoluble inalcohol. Consequently, when such an ink is to be used it is preferableto prepare a decalcomania 5 paper especially for them which will beexactly like that above described except that the coats will bereversed. In other words, the first and third coats will consist of thegum sandarac rosin mixture while the intermediate coat 2 will have 10cumar, or its equivalent, as its essential constituent.

In applying decalcomanias of this type to veneer and other waterabsorbing bodies, some absorption of the solvent may occur, but thesesol- 15 vents are so volatile that they evaporate rapidly and do notproduce any warping of the veneer. Consequently, they completely avoidthe objection above described to the use of common forms ofdecalcomanias. As above stated, a consider- 20 able variety of thesevolatile solvents of a hydrocarbon nature are available at reasonableprices so that the expense involved in the use of such a solvent insteadof water is not a serious practical objection.

Having thus described my invention, what I desire to claim as new is:

1. A decalcomania paper comprising a suitable backing sheet, a waterresistant coating carried by said sheet to take decalcomania printing,and 30 a protective coating of resinous water resistant material betweenthe first mentioned coating and said sheet, said protective coatingbeing substantially insoluble in a solvent which readily dissolves theother coating. 85

2. A decalcomania paper comprising a suitable backing sheet, a waterresistant resinous coating carried by said sheet to take decalcomaniaprinting, and an intermediate coating of resinous water resistantmaterial bonding the first coating to 40 said backing sheet, each ofsaid coatings being readily soluble in a solvent to which the othercoating is highly resistant.

'3. A decalcomania paper comprising a suitable backing sheet and aplurality of water resistant 45 resinous coatings on one face of saidsheet in superposed relationship, the adjoining coatings beingdifferentially soluble in non-aqueous solvents.

4. A decalcomania paper comprising a suitable backing sheet, and aplurality of coatings of water resistant resinous material in superposedrelationship on one face of said sheet, each of said coatings beingsoluble in a. solvent to which the adjoining coating is highlyresistant.

5. A decalcomania paper comprising a suitable backing sheet, a pluralityof coatings of water resistant material in superposed relationship onone face of said sheet, the predominating constituent of one of saidcoatings being coumarone-indene resin while the other consistsessentially of a mixture of gum sandarac and rosin.

6. A decalcomania paper comprising a suitable backing sheet, and threewater resistant coatings carried by one face of said backing sheet 65 insuperposed relationship to each other, one of said coatings beingsoluble in alcohol. another in a petroleum distillate, and the third inone only of said solvents, the middle coatme being substantiallyinsoluble in the solvent for the coatings on opposite sides of it, andthe latter being substantially insoluble in the solvent for the middlecoating.

7. A decalcomania paper comprising a. it b backing sheet and a waterresistant coating of a aoaaeoa resinous nature carried by said sheet totake decalcomania printing, said coating being bonded to said sheet by awater resistant union releasable by a non-aqueous volatile solvent.

8. A decalcomania paper comprising a suitable backing sheet and a waterresistant coating carried by said sheet to take decalcomania printing,said coating being highly resistant to the common solvents used inprinting inks and being bonded to said sheet by a water resistant unionreleasable by a non-aqueous solvent of a hydrocarbon nature.

9. A decalcomania paper comprising a. suitable backing sheet, a waterresistant coating of a resinous nature carried by said sheet to takedecalcomania printing, said coating being resistant to the commonsolvents used in printing inks, and a protective coating of waterresistant material bonding said resinous coating to said backing sheet,said resinous coating being substantially insoluble in a solvent whichreadily dissolves the protective coating.

DAVIS.

